The Elemental Estimate layout and grouping of items will be used in this example. When building up composite rates for Approximate Quantities, you have to follow some basic principles. We are going to illustrate a composite rate build-up for Internal Walls:

Superstructure 115mm internal one brickwall 2900mm high, 150mm wide reinforcement every third course, including one coat cement plaster on smooth plastered walls both sides, one coat plaster primer and two coats Plascon Wall paint on both sides.

Step 1

First, you have to determine the Group unit of measurement. When you are measuring the internal walls (superstructure) in Elemental or Approximate Quantities estimating, the group unit of measurement is the square metre (m2).

Step 2

The second step is listing all associated Bill items that can be mapped to Internal Walls by area. These are:

115mm one brickwall – (m2) Rate – R131

75mm wide brick reinforcement – (m) Rate – R2.50

One coat cement plaster – (m2) Rate – R30

Painting (undercoat and overcoat) – (m2) Rate – R30

Step 3

Since your Group unit is the square metre (m2), you should convert the Bill item rates to Cost per Square Metre.